Atomically Fe(Ⅲ) anchored metal-organic frameworks-based fluorescent nanozyme for smartphone-adopted chemiluminescence-fluorescence dual-mode analysis of Uric acid.

Background: Chemiluminescence (CL) analysis is a promising analytical method with advantages including easy operation, high sensitivity and simple instrument. However, the single CL mode usually suffered from poor stability and reproducibility as a result of the flash-type nature of luminescent molecules, leading to false positive or negative results in practical applications. Dual-mode detection is an advanced sensing methodology that identifies analytes through independent output signals. This approach has the ability to circumvent the inherent constraints of individual sensing modes while integrating their respective strengths, thereby yielding a synergistic enhancement in the detection system.
Results: Herein, a chemiluminescence-fluorescence (FL) dual-mode analysis and imaging system is designed by constructing an atomically Fe(Ⅲ) anchored PCN-224 peroxidase-mimicking nanozyme (PCN-224/Fe(Ⅲ)) and achieve an ultrasensitive detection of Uric Acid (UA). The multifunctional PCN-224/Fe(Ⅲ) serves as a high-efficiency co-reaction promoter in the generation of reactive oxygen species (ROS) in both the CL and FL system, while also demonstrating exceptional capabilities as fluorescent nanoprobes. Ultimately, a smartphone-adopted CL imaging device was developed to achieve a visual CL detection through the design of portable paper-based chips. Besides, with the assistance of the TMB-mediated fluorescence energy resonance transfer, the fluorescent PCN-224/Fe(Ⅲ) nanoprobes exhibited good fluorescence detection performance for UA. The limit of detection was achieved as low as 2.45 × 10 ^-10  M and 1.99 × 10 ^-9  M in the CL and FL mode, respectively.
Significance: This study engineered an atomically Fe(Ⅲ)- MOF-based multifunctional nanozyme and developed an innovative approach for creating CL-FL dual-mode analysis and imaging detection for UA. The proposed CL-FL dual-mode detection system not only provided a portable and sensitive method for UA detection but also offered valuable insights into the mechanism of the co-reaction promoter enhanced CL and FL analysis.
Competing Interests: Declaration of competing interest The authors declare no competing financial interest.
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